Hops are the flowers (also called seed cones or strobiles) of the hop plant Humulus lupulus. They are used primarily as a bittering, flavouring, and stability agent in beer, to which, in addition to bitterness, they impart floral, fruity, or citrus flavours and aromas. Recent evidence has suggested Hops improves sleep quality by modulating GABA receptors thereby increasing GABA activity in the brain.

• Franco L, Sánchez C, Bravo R, Rodriguez A, Barriga C, Juánez JC. The sedative effects of hops (Humulus lupulus), a component of beer, on the activity/rest rhythm. Acta Physiol Hung. 2012;99(2):133-139. doi:10.1556/APhysiol.99.2012.2.6
• Franco L, Sánchez C, Bravo R, et al. The sedative effect of non-alcoholic beer in healthy female nurses. PLoS One. 2012;7(7):e37290. doi:10.1371/journal.pone.0037290

Lemon balm (Melissa officinalis) is lemon scented herb and is native to Europe, North Africa, and West Asia. Sources date the medicinal use of lemon balm to over 2000 years ago through the Greeks and Romans. In traditional medicine, M. officinalis leaves have been prescribed for the treatment of disorders of the gastrointestinal tract, nervous system, liver, and bile. Several studies show that lemon balm combined with other calming herbs (such as valerian, hops, and chamomile) helps reduce anxiety and promote sleep by increasing the release of chemical messengers (e.g. GABA) inside the brain.

• Haybar H, Javid AZ, Haghighizadeh MH, Valizadeh E, Mohaghegh SM, Mohammadzadeh A. The effects of Melissa officinalis supplementation on depression, anxiety, stress, and sleep disorder in patients with chronic stable angina. Clin Nutr ESPEN. 2018;26:47-52. doi:10.1016/j.clnesp.2018.04.015
• Ranjbar M, Firoozabadi A, Salehi A, et al. Effects of Herbal combination (Melissa officinalis L. and Nepeta menthoides Boiss. & Buhse) on insomnia severity, anxiety and depression in insomniacs: Randomized placebo controlled trial. Integr Med Res. 2018;7(4):328-332. doi:10.1016/j.imr.2018.08.001

Passion flower is a climbing vine that is native to the southeastern United States, and Central and South America. Traditionally it has often been used to treat lack of sleep. Recent literature has reaffirmed this belief and postulates that it does so by inhibiting reuptake of GABA in the brain so as to increase its concentration.

• Guerrero FA, Medina GM. Effect of a medicinal plant (Passiflora incarnata L) on sleep. Sleep Sci. 2017;10(3):96-100. doi:10.5935/1984-0063.20170018
• Ngan A, Conduit R. A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality. Phytother Res. 2011;25(8):1153-1159. doi:10.1002/ptr.3400

Melatonin also known as sleep hormone is produced by the pineal gland located in the brain. Melatonin is a serotonin-derived hormone which modulates sleep patterns in both circadian and seasonal cycles. As a dietary supplement, it is often used for the short-term treatment of sleep onset insomnia and insomnia related to altered sleep schedule e.g., jet lag, shift work.

• Ferracioli-Oda, E., Qawasmi, A., & Bloch, M. H. (2013). Meta-analysis: melatonin for the treatment of primary sleep disorders. PloS one, 8(5), e63773. https://doi.org/10.1371/journal.pone.0063773
• Tordjman, S., Chokron, S., Delorme, R., Charrier, A., Bellissant, E., Jaafari, N., & Fougerou, C. (2017). Melatonin: Pharmacology, Functions and Therapeutic Benefits. Current neuropharmacology, 15(3), 434–443. https://doi.org/10.2174/1570159X14666161228122115
• Costello, R. B., Lentino, C. V., Boyd, C. C., O'Connell, M. L., Crawford, C. C., Sprengel, M. L., & Deuster, P. A. (2014). The effectiveness of melatonin for promoting healthy sleep: a rapid evidence assessment of the literature. Nutrition journal, 13, 106. https://doi.org/10.1186/1475-2891-13-106